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ABSTRACT Plants require water and nutrients for survival, although the effects of their availabilities on plant fitness differ amongst species. Genome size variation, within and across species, is suspected to influence plant water and nutrient requirements, but little is known about how variations in these resources concurrently affect plant fitness based on genome size. We examined how genome size variation between autopolyploid cytotypes influences plant morphological and physiological traits, and whether cytotype‐specific trait responses differ based on water and/or nutrient availability.Diploid and autotetraploidSolidago gigantea(Giant Goldenrod) were grown in a greenhouse under four soil water:N+P treatments (L:L, L:H, H:L, H:H), and stomata characteristics (size, density), growth (above‐ and belowground biomass, R/S), and physiological (Anet,E,WUE) responses were measured.Resource availabilities and cytotype identity influenced some plant responses but their effects were independent of each other. Plants grown in high‐water and nutrient treatments were larger, plants grown in low‐water or high‐nutrient treatments had higherWUEbut lowerE, andAnetandErates decreased as plants aged. Autotetraploids also had larger and fewer stomata, higher biomass and largerAnetthan diploids.Nutrient and water availability could influence intra‐ and interspecific competitive outcomes. AlthoughS. giganteacytotypes were not differentially affected by resource treatments, genome size may influence cytogeographic range patterning and population establishment likelihood. For instance, the larger size of autotetraploidS. giganteamight render them more competitive for resources and niche space than diploids.
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How and why do species break a developmental trade‐off? Elucidating the association of trichomes and stomata across species
Abstract PremisePrevious studies have suggested a trade‐off between trichome density (Dt) and stomatal density (Ds) due to shared cell precursors. We clarified how, when, and why this developmental trade‐off may be overcome across species. MethodsWe derived equations to determine the developmental basis forDtandDsin trichome and stomatal indices (itandis) and the sizes of epidermal pavement cells (e), trichome bases (t), and stomata (s) and quantified the importance of these determinants ofDtandDsfor 78 California species. We compiled 17 previous studies ofDt–Dsrelationships to determine the commonness ofDt–Dsassociations. We modeled the consequences of differentDt–Dsassociations for plant carbon balance. ResultsOur analyses showed that higherDtwas determined by higheritand lowere, and higherDsby higherisand lowere. Across California species, positiveDt–Dscoordination arose due toit–iscoordination and impacts of the variation ine. ADt–Dstrade‐off was found in only 30% of studies. Heuristic modeling showed that species sets would have the highest carbon balance with a positive or negative relationship or decoupling ofDtandDs, depending on environmental conditions. ConclusionsShared precursor cells of trichomes and stomata do not limit higher numbers of both cell types or drive a generalDt–Dstrade‐off across species. This developmental flexibility across diverse species enables differentDt–Dsassociations according to environmental pressures. Developmental trait analysis can clarify how contrasting trait associations would arise within and across species.
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- PAR ID:
- 10536483
- Publisher / Repository:
- American Journal of Botany
- Date Published:
- Journal Name:
- American Journal of Botany
- Volume:
- 111
- Issue:
- 5
- ISSN:
- 0002-9122
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/ajb2.16328
